Telecommunications networks involve an exceedingly complex arrangement of highly technical components that almost magically allow people separated by vast distances to speak to each other. These networks have evolved from an analog system where a human operator was involved in completing a circuit between two rotary dial telephones to modern digital communications that use softswitch networks and voice over Internet Protocol (VoIP), among other technologies.
FIG. 1 is a diagram illustrating some of the components included in a conventional modern telecommunication network 10. Generally speaking, the telecommunication network includes a class 5 network 12 where various customers 14 connect to the network and it also includes a class 4 network 16 that handles long distance calling. The class 5 network may be an instance of a class 5 network, and there may be several instances of such class 5 networks (not shown) interconnected through the class 4 network. From a high level perspective, a person at a customer location initiates a call using a phone 18, directly from which may be a conventional phone, a VoIP phone, etc. Customer premise equipment 20, such as an integrated access device (IAD), an Internet Protocol Private Branch Exchange (IP-PBX) device, or the like routes the call to a geographically proximate class 5 telecommunications network using a trunk 22 between the customer and the class 5 network. In this example, the customer's are typically businesses or other organizations, rather than individual users, with a number of the organization's members having phones. An IP-PBX is a business telephone system that allows the organization to manage a number of different internal phone numbers and routes calls to the correct phone. The IP-PBX also facilitates connections of voice and data communications to a conventional public switched telephone network (PSTN), as well as data networks (as in the present example). An IAD, on the other hand, provides less sophisticated services compared to an IP-PBX while similarly allowing voice and data connections with data networks. Both devices allow for VOIP calls.
At an edge of the class 5 network, the call is received and processed by a session border controller (SBC) 24. At a high level, the SBC is involved in processing a VOIP call, along with a class 5 application server (e.g., a softswitch) 26, within the class 5 network. The class 5 network, which includes softswitch infrastructure, provides enterprise services and specifically session initiation protocol (SIP) trunking services. The term “SIP trunking services” refers to the use of VOIP and the SIP protocol to provide telecommunication services between a customer with an IP-PBX, IAD, or similar CPE, and the class 5 network. The class 5 application server provides several functions including call admission control (CAC), share concurrent call path (CCP) enforcement across all trunk groups (TGs) for a customer of the class 5 network, and class features such as call waiting, call forwarding, call transfer, etc. The class 5 network, in this example, initially receives and processes calls from retail customer. In contrast, the class 4 network 16, to which the class 5 network is connected at the SBC 24C, processes long distance calls. Hence, in a typical scenario, a call is first processed by and passes through a class 5 network and is handed to the class 4 network. From the class 4 network, the call proceeds to another destination 28 for termination. For example, the class 4 network 28A may be connected with a PSTN network that terminates the call. Thus, retail customers where a call originates or terminates are not directly connected to class 4 networks. In contrast, wholesale customers 30 that do not require any class 5 services connect directly to the class 4 network through the SBC 24C. Also, as shown on the left side of FIG. 1, a retail customer's PBX may interconnect directly to a class 4 network to receive long distance services and/or toll free services that do not require any class 5 features.
While highly functional, reliable and proven, the telecommunication network illustrated in FIG. 1 nonetheless may benefit form various improvements. The investment in building such networks is tremendous. However, as such networks are built and expanded, several redundancies and inefficiencies emerge. For example, to extend the geographic reach of the class 4 network, adjunct class 5 networks are built around the edges of the class 5 network. Similarly, to add customers to the class 5 networks, additional edges are built around the class 5 network to provide connections to customers. Thus, in essence, there are two complex and expensive steps required to process a call from a retail customer on a class 4 network. In another example, customers typically maintain their own CPE equipment that can provide much of the same features as a class 5 switch. It is with these issued in mind, among others that various features of the present disclosure were conceived.